What Lurks at Midnight
The biggest one left is Carcosa and the Lake of Hali; from The King in Yellow by Robert W. Chambers, later assimilated into the Cthulhu Mythos. (Also, for the pedantic win, Chambers borrowed the place names "Carcosa," "Hastur," and I think maybe "Hali" from short stories by Ambrose Bierce.)Probably might be a few other references in there.
(Yes, Hastur is a place. Blame August Derleth for getting it and so many other things wrong, even as you praise him for popularizing Lovecraft's work.)